token welcome post

Discussion in 'Introduce Yourself' started by luke_mcmahon85, May 2, 2007.

  1. hi! this is my welcome post, i really really want to post pictures of my project, but alas, have just joined this site, tommorow i will put some up. i'm really dissapointed i only just found this site, as i'm almost finished my build. i'm also dissapointed that i went the hard way to making a motorised bicycle, i only realised there were kits to do this type of thing a little while into my build (after i had bought the bike and engine) oh well...maybe next time.

    given that i was unaware of the kits that seem so popular on this site, i simply bought an old 60's or 70's dragster bike (that's what we call them here in australia, i guess it's the same in the US) and a 49cc engine off a chinese pocket bike. i then modified the frame and welded on engine mounts etc. also given that i'm not a big fan of exercise, i did away with the pedals all together. so i have the engine mounted in the frame, with a tiny sprocket from the left hand side having a chain going to a large sprocket welded on to where the left pedal would be, and then where the right pedal would be, there is a small sprocket that leads a chain that goes to a large sprocket welded onto the rear hub...which is a sturmey archer 3-speed internal hub, which i'm hoping will give me 3 gears. this way i have enough power to take off and still get a reasonable high top speed, all without pedalling. the engine has a centrifugal clutch, and a pull start, so i'm hoping to get the idle and clutch adjustments right so that i will be able to bring the bike to a complete halt, and keep the engine running, just like a motorbike or a go-kart....

    i have had it running, and it takes off fine, and is quite fast (haven't got the gear changer hooked up, so this is all in 1st) but i keep munching the funny rear grooved washers that are used to hold the hub in place (these seem to be unique to SA rear hubs so if it continues i mihgt have to go with a fixed gear rear hub...ah well). anyway, i will post pictures tommorow...

  2. Chopper

    Chopper Guest

    hey Luke, where are you?.... love to see some pics of your project.
  3. hey, i'm in melbourne, i'll post some pictures as soon as i'm allowed, but if you want to check some out, you can go to my myspace page, hehe, it won't even let me write the address, but my user name is luke_mcmahon85 so just put that in if you're keen and check out my blogs, there's even a video of me starting it for the first time
  4. nashe

    nashe Guest

    Ooh. I like the video you posted in your blog! Mean little bike, there.

    .. and I enjoy the terrifying Australian bird (?) noises in the background.
    Sure as heck doesn't sound like that in any backyard in Missouri. :shock:

    But .. yeah. God jobby on the bike, Luke! :smile:
  5. srdavo

    srdavo Active Member

    can't wait to see pics of your build. I am very interested in home-built designs.
  6. okay, picture time....

    this is the bike when i bought it for 5 is a roadmaster 20inch stepthrough (girls) bike


    after a little work, welding up engine mounts, removing backbone and bending new one to make it more like a boys frame, and also to fit the engine


    badly welded custom exhaust...


    whole bike, with both chains, crappy plastic gas tank, going to make a better motorcycle style one


    go to to see the video

    i've been able to ride it now for a while, but the front chain keeps jumping off, so i might need to add a chain tensioner....also better brakes as i just nailed myself on it, hahaha, i'd better go buy a helmet...ooops...
  7. azbill

    azbill Active Member

    hey ...I can weld an exhaust like that
    very ingenius build dude :shock: :shock:
    good job 8) 8)
  8. Guest

    Guest Guest

    Engine make and size?
  9. Welcome to the forum, Luke! Love that build 8)

  10. cheers, it's a chinese 49cc engine off a pocket bike, they're these little tiny motorbikes, it puts out a fair bit of power for its size, and what's cool is that there are all kinds of aftermarket updates for them, like fibreglass or carbon fibre reeds, advanced timing keys, full circle cranks and two piece head kits to up the displacement as well as compression